1. Field of the Invention
The present invention relates to a display device and a method for manufacturing the same. The invention further relates to a television device utilizing the display device and the method for manufacturing thereof.
2. Description of the Related Art
A thin film transistor (hereinafter, referred to as a TFT) and an electronic circuit using the TFT have been formed as follows: various kinds of thin films such as a semiconductor, an insulator, and a conductor are laminated over a substrate, and the thin films are processed into a predetermined pattern by photolithography. Photolithography is a technique for transferring a pattern such as a circuit, which is formed of a light-shielding material over a flat transparent plate that is referred to as a photomask, over a substrate by utilizing light. The technique has been widely used in a step of manufacturing a semiconductor integrated circuit, and the like.
In the conventional manufacturing process using the photolithography, many steps such as exposing, developing, baking, and separating are required even in the case of handling a mask pattern, which is formed of a photosensitive organic resin material that is also referred to as a photoresist. Increasing the number of steps for photolithography increases the manufacturing cost eventually. In order to overcome such a problem, research for manufacturing a TFT has been attempted without carrying out the photolithography step (e.g., see patent document 1).
In the technique as disclosed in the patent document 1, however, the photolithography steps, which are performed several times in the process for manufacturing a TFT, are only partly replaced by the printing method. Therefore, the technique cannot drastically contribute to reducing the number of steps for photolithography. Further, an exposure apparatus used for transferring a mask pattern in over a substrate the photolithography is an apparatus in which a pattern with a size of several microns or more and 1 micron or less is transferred. Therefore, it is technically impossible to expose a large-size substrate with 1 m on a side at once, in principle.
[Patent document 1]: Japanese Patent Application Laid-Open No. Hei 11-251259